As Engines Sputter To Life, Vintage Spacecraft Turns Toward Moon

With a comet fly-by and a solar orbit behind it, ISEE-3 has now revved its engines for a swing past the moon.

Mark Maxwell
/ Courtesy ISEE-3 Reboot Project

Originally published on July 9, 2014 8:56 am

A gung-ho group of space enthusiasts has started the process of putting a vintage NASA spacecraft on a new flight path, so that this venerable piece of hardware will be able to do useful science once again.

The old spacecraft, called ISEE-3, launched back in August 1978. Its original job was to hang out between the Earth and the Sun and study their interactions. But in the 1980s, a NASA mission designer named Bob Farquhar helped convince the agency to send it off on a crazy new trajectory — so the U.S. could beat all the other nations of the world to make the first visit to a comet.

Since then, ISEE-3 has been on a long, looping orbit around the Sun. But recently, NASA agreed to let some volunteers figure out how to reconnect with this obsolete space equipment and take command. The effort is called the ISEE-3 Reboot Project.

In May, the team managed to say hello to ISEE-3 in its archaic machine language — and the spacecraft responded.

"Our spacecraft does not have a computer. I mean, it's truly accurate to say your toaster is smarter," says Keith Cowing, a former NASA guy who is heading up the project along with a partner named Dennis Wingo.

Last week, the team fired the spacecraft's engines for the first time since 1986. That was just to get it spinning the right way, but the success confirmed that the propulsion system was still working.

Now, as of Tuesday, they've been sending commands for engine burns that will actually change the vehicle's course.

"And the first burn went well, we thought," says Cowing, "and then it stopped and we got indications that the spacecraft had changed its speed, which is what you want."

But the second attempt to fire the engines didn't go as smoothly.

"It's a cranky old spacecraft that — knock on wood — does what we tell it to do most of the time," says Cowing. "We kind of knew we might be doing this over the course of a day or two, so this isn't surprising."

Cowing says they will keep working at the course correction in the coming days. The spacecraft should fly within about 30 miles of the moon's surface in August.

Then some additional commands could take it into an orbit near Earth once again, where it could join other, younger satellites that monitor space weather.